Production of gas containing sulfur dioxide



United States Patent Ice 2,761,762

Patented Sept. 4, 1956 section of which preferably widens vupwardly. Such 2,761,762 q fiiescent zones may be used with turbulent layer furnaces 0 any cross-section, as for example circular, elliptical, PRODUCTION OF SULFUR annular or polygonal. Upon leaving the turbulent layer,

the reaction gases undergo a reduction in speed, which Adolf J ohannsen, Ludwigshafen (Rhine), Willi Danz, I IS accentuated by conical construction of the quiescent Ludwigshafen (BhmQ-Oggersheim, Wilhelm Pfannzone, so that the entrained particles in the ascending gas 211153113, lannheim, and Herbfrt dfudxggls haftg stream gradually lose their upwardly directed speed in me ermany asslg rs o a e nncon e Soda Fabnk Akfiefigeseus Ludwigshafen e), s quence of the counteracting force of gravitation and fall back into the turbulent layer. Germany It is also possible, however, to use the flue dust which N0 Drawing Application February 19 1952, has been entrained by the reaction gases and deposited S i l N 272,506 in dlst chtambers, cyclones or the like, this being returned to tr e tur ulent layer by free fall or by conveyer devices; Clalms Priority! aPPHcafion Germany March 6! 1951 it has been found to be preferable to introduce it into the 2 Claim (CL 23 177) lower part of the turbulent layer near to its bottom surface and the grate through which the oxygen-containing This invention relates to the production of gases congas is introdlleed- In this y a coilsteht loosening of taining sulfur dioxide by roasting comminuted sulfur the coarse-grained material which becomes enriched in minerals the lower parts of the layer is effected and the formation An advantageous method f roasting ufur i l of the turbulent motion thus facilitated. The flue dust having a grain size predominantly within the range of 0.1 entrained y the reaction gases has a grain SiZe mainly to 10 millimeters has already been described by us in our below 2 millimeters- If it is reintroduced into the copending applicationSerial No. 192,374, filed October turbulent y by tee-$011 0f the large Surface p- 26, 1950, according to which the minerals are supplied 25 meht of these fine-grained Particles in Comparison With to a layer in random turbulent motion, the said layer their small Weight there is imparted thereto y the P- consisting of substantially roasted material, being kept WardlY flowing gases a quantity of motion pp to the at the roasting temperature and being traversed in an upforce of gfavitatioil- These p y directed fine P ward direction by oxygen-contai in gases i a amount ticles transmit, in collision With the coarse solid'particles suiiicient to maintain the turbulent motion. In order to (Which Cannot be directly carried P y the gases themavoid exceeding the permissible roastin temperature selves by reason of their small surface development relain the said process there may be added to the turbulent lively to their Weight), a motion impulse Which iS Suflayer cold roasted ore of the sulfur minerals to be procfieient t0 elleet temporarily a Vertically p y directed essed or other inert substances or also solid substances motion to even the Coarse Particles and h s to ini iate which split off sulfur dioxide by an endothermic reaction. a random turbulent motion of the Particles undo! he We have now found that in the roasting of sulfur counteraction of the force of gravitationminerals of which the grain size is too coarse for the Instead or together With, the flue dust, there m y formation of a uniform turbulent motio fo example also be reintroduced those fine portions of the roasted of a grain size up to about 12 millimeters, and in par- Ore which are directly removed from the turbulent layer,

ticular in the case of materials in which the constituents for example through all overflow, and from W ch if having a grain size above about 6 millimeters strongly n cessary the coarse-grained portion may be separated. predominate, it is possible to maintain a turbulent motion Cooling of e r a ed Ore before its return into the in the layer sufficient for carrying out th roasting turbulent layer is neither necessary nor preferable proprocess by introducing into the layer, simultaneously vided that heat-absorbing members are provided in the with the said coarse-grained material, other solid subturbulent layer for the utilisation of the roasting heat stances which do not soften at the roasting temperature for the recovery of yand which are of finer grain or which disintegrate during W at W a m is: the turbulent motion, 1. In a process for the production of gases containing Generally speaking it is advantageous to employ addisulfur dioxide by roasting comminuted sulfur minerals tional substances which mainly have a grain size of less With oXygeii-eotlteihiilg gases in a layer of Substantially than about 3 millimeters. By this measure it is possible roasted material kept in random turbulent motion Within to roast by the turbulent layer process coarse sulfur t e c fi of the layer y the Said g he improveminerals with which otherwise difliculties might occur by ment which comprises feeding into the turbulent layer sulreason of agglomeration and slag formation. As addifur minerals having a grain size of up to about 12 miltional substances there may be mentioned in particular limeters and a predominating grain size of above about 6 the finegrained roasted ore such as is formed in the millimeters, and simultaneously introducing into the lower a turbulent layer by decrepitation and attrition from the part of the turbulent layer near the bottom surface thereinitially introduced sulfur minerals and which is in part of roasted Ore Particles Previously removed from th carried away from the turbulent layer as flue dust by the 0 layer and which have a grain size of less than b t 3 roaster gases. It is, however, also possible to add other 6 m llim t fa ta h tur ul nt motion. inert substances which do not soften at the roasting tem- In a Process the Production of gases Containing perature, or substances which give ofi sufur dioxide by sulfur dioxide by roasting comminuted sulfur minerals an endothermic reaction without softening, as for exwith oxygen-containing gases in a layer of substantially ample the sulfates of iron, magnesium or calcium, or roasted material kept in random turbulent motion within which themselves contain sulfur which is capable of being the confines of the layer by the said gases, the improveroasted out, as for example fine-grained flotation pyrites ment which comprises feeding into the turbulent layer or gas purification masses. sulfur minerals having a grain size of up to about 12 The return of the fine-grained roasted ore can advanmillimeters and a predominating grain size of above about tageously be effected by arranging above the turbulent 6 millimeters, and simultaneously introducing into the layer a quiescent zone the height of which is at least lower part of the turbulent layer near the bottom surface about four times that of the turbulent layer and the'crossthereof roasted ore dust deposited from the roaster gases 4 Orgozaly Apr. 1, 1952 Perry Nov. 11, 1952 Cyr Dec. 9, 1952 Roberts Ian. 13, 1953 Lewis May 5, 1953 OTHER REFERENCES Coke and Gas, London, -Westminster S. W. 1, February 1949, pages 64-68. 

1. IN A PROCESS FOR THE PRODUCTION OF GASES CONTAINING SULFUR DIOXIDE BY ROASTING COMMINUTED SULFUR MINERALS WITH OXYGEN-CONTAINING GASES IN A LAYER OF SUBSTANTIALLY ROASTED MATERIAL KEPT IN RANDOM TURBULENT MOTION WITHIN THE CONFINES OF THE LAYER BY THE SAID GASES, THE IMPROVEMENT WHICH COMPRISES FEEDING INTO THE TURBULENT LAYER SULFUR MINERALS HAVING A GRAIN SIZE OF UP TO ABOUT 12 MILLIMETERS AND A PREDOMINATING GRAIN SIZE OF ABOVE ABOUT 6 MILLIMETERS, AND SIMULTANEOUSLY INTRODUCING INTO THE LOWER PART OF THE TURBULENT LAYER NEAR THE BOTTOM SURFACE THEREOF ROASTED ORE PARTICLES PREVIOUSLY REMOVED FROM THE LAYER AND WHICH HAVE A GRAIN SIZE OF LESS THAN ABOUT 3 MILLIMETERS TO FACILITATE THE TURBULENT MOTION. 